--- title: "Your Analytics Tool Contacts 7 Domains. Here Is Why." description: "Every external domain is a DNS lookup, a privacy risk, and a GDPR liability. We mapped every domain contacted by 9 analytics tools." canonical_url: "https://sealmetrics.com/blog/analytics-tools-external-domains/" lang: "en" date_modified: 2026-05-04 content_type: "blog" owner: "content" llm_priority: "useful" last_verified: "2026-05-04" source: https://sealmetrics.com/blog/analytics-tools-external-domains/ publisher: Sealmetrics --- Privacy # Your Analytics Tool Contacts 7 Domains. Here Is Why That Matters. March 4, 2026 4 min read By [Rafa Jiménez](https://sealmetrics.com/authors/rafa-jimenez/) ## Key Takeaways - Adobe Analytics contacts 4 third-party domains per page load, adding 600-1,200 ms of network overhead; GA4 contacts 3 domains costing 450-900 ms. - Sealmetrics contacts only 1 domain — your own subdomain — with zero third-party requests, zero cross-border transfers, and zero additional DNS lookups. - Each third-party US domain is a GDPR legal surface requiring Standard Contractual Clauses and a Transfer Impact Assessment. - Third-party domains are the primary target of ad blockers and browser privacy features — first-party collection is indistinguishable from normal website requests. Every time a visitor loads your site, your analytics tool phones home. Not to one server — to several. Each external domain your analytics contacts means a DNS lookup (50–100 ms), a TLS handshake (100–200 ms), a data transfer to a third party, and — if that domain resolves to a US server — a potential GDPR cross-border transfer issue that your DPO needs to document. We opened Chrome DevTools on a clean browser profile and mapped every unique domain contacted by nine analytics tools. Then we ran `dig` on each domain to identify where the data actually goes. ## What we mapped For each tool, we recorded: the total number of unique domains contacted, how many of those are third-party (not your own domain), where the data lands geographically, and the specific domain names involved. The methodology is reproducible — steps are at the bottom of this post. ## The results | Tool | Domains | Third-party | Data destination | Domains contacted | | --- | --- | --- | --- | --- | | Sealmetrics | 1 | 0 | EU (customer's subdomain) | collect.yourdomain.com | | Plausible | 1 | 1 | EU | plausible.io | | Fathom | 1 | 1 | US/EU | cdn.usefathom.com | | Simple Analytics | 1 | 1 | EU | queue.simpleanalyticscdn.com | | Piwik PRO | 2 | 2 | EU/US | yourname.piwik.pro, yourname.containers.piwik.pro | | Mixpanel | 2 | 2 | US | cdn.mxpnl.com, api-js.mixpanel.com | | PostHog | 2 | 2 | US/EU | us.posthog.com, us-assets.i.posthog.com | | Google Analytics 4 | 3 | 3 | US/EU (CDN) | googletagmanager.com (US), google-analytics.com (EU CDN), region1.google-analytics.com (US) | | Adobe Analytics | 4 | 4 | EU (CDN/AWS) | assets.adobedtm.com (Akamai CDN), dpm.demdex.net (AWS Dublin), sc.omtrdc.net, d1.sc.omtrdc.net | Sealmetrics 1 (0 3P) Plausible 1 (1 3P) Fathom 1 (1 3P) Simple Analytics 1 (1 3P) Piwik PRO 2 (2 3P) Mixpanel 2 (2 3P) PostHog 2 (2 3P) GA4 3 (3 3P) Adobe 4 (4 3P) The range is stark. Sealmetrics contacts one domain — your own. Adobe Analytics contacts four third-party domains, all resolving to US infrastructure. ## The performance cost Every unique domain requires two network round-trips before a single byte of data moves: a DNS resolution (50–100 ms) and a TLS handshake (100–200 ms). That is 150–300 ms per domain, on the first visit. Adobe Analytics contacts 4 domains. That is 600–1,200 ms of network overhead before analytics data even begins to transfer. GA4's 3 domains cost 450–900 ms. Sealmetrics, with one first-party domain, costs 150–300 ms — and that domain is already resolved because it is a subdomain of your own site. On a mobile connection with 80 ms RTT, four domains add nearly a full second of latency. That latency competes with your content, your images, your fonts. It is not theoretical — it shows up in Largest Contentful Paint and Interaction to Next Paint. One domain, zero third parties — collection runs on your own subdomain. Compare that with the domain map your current stack just produced. [Book a demo](https://sealmetrics.com/demo/)[See pricing](https://sealmetrics.com/pricing/) ## The privacy and GDPR cost Post-Schrems II, every data transfer to a US entity requires[Standard Contractual Clauses](https://eur-lex.europa.eu/eli/reg/2016/679/oj) plus a Transfer Impact Assessment. Each third-party US domain is a legal surface your organization must document and defend. Your DPO needs to account for each one. GA4 sends data to three Google-owned domains, all resolving to US infrastructure. Adobe sends data to four domains — including `dpm.demdex.net`, Adobe's audience management platform, which processes data in the United States. Each domain is a separate data processor relationship that requires [GDPR compliance documentation](https://sealmetrics.com/glossary/gdpr-analytics-compliance/). Zero third-party domains means zero cross-border transfer issues. One domain — your own — means one data processing relationship: yours. ## The data residency question Where do the bytes actually go? We ran `traceroute` and GeoIP lookups on every domain in the table. GA4's primary endpoint — `googletagmanager.com` — resolves to Mountain View, California (216.58.215.136). Its collect endpoint `region1.google-analytics.com` resolves to Austell, Georgia (216.239.34.36). Note that [`google-analytics.com`](https://support.google.com/analytics/answer/12159447) serves from a CDN that may resolve to EU edge nodes, but the data processing still occurs on Google's US infrastructure. Adobe's domains use CDN and AWS endpoints — `assets.adobedtm.com` serves via Akamai (we measured Madrid), `dpm.demdex.net` resolves to AWS Dublin (54.246.175.19). CDN edge location does not equal data residency — the processing and storage may still happen elsewhere. Sealmetrics resolves to the customer's own subdomain (e.g. `collect.yourdomain.com`), which points to EU infrastructure in Barcelona, Spain (91.242.131.41, Noraina) via a CNAME record. The [data residency](https://sealmetrics.com/glossary/analytics-data-residency/) is verifiable: run `dig collect.yourdomain.com` and check the IP yourself. ## First-party vs third-party collection The distinction matters for more than compliance. Third-party domains are the primary target of ad blockers, browser privacy features, and content security policies. When your analytics runs on `googletagmanager.com` or `demdex.net`, every blocklist in the world knows to intercept it. Sealmetrics uses [cookieless first-party collection](https://sealmetrics.com/how-it-works/) through a CNAME on the customer's own domain. To the browser, to DNS resolvers, and to ad blockers, it looks like a first-party request — because it is one. No third-party domain to block, no cross-border transfer, no additional DNS lookups. The [collection architecture](https://sealmetrics.com/how-it-works/) is designed so that the analytics request is indistinguishable from any other request to your own site. ## How we mapped this The test is reproducible. Here are the steps: 1. Open Chrome with a clean profile (no extensions, no cached data). 2. Open DevTools → Network tab. Enable “Preserve log” and disable cache. 3. Install each analytics tool on a minimal HTML page, one at a time. 4. Load the page. Record every unique domain in the Network tab. 5. Run `dig [domain]` on each domain to get the resolved IP address. 6. Use GeoIP lookup on each IP to determine the physical location of the server. 7. Classify each domain as first-party (your domain) or third-party (vendor domain). No special tools required. Anyone with Chrome and a terminal can verify these results in under an hour. ## The bottom line Every external domain your analytics contacts is a performance penalty, a privacy liability, and a legal surface. Four domains means four DNS lookups, four TLS handshakes, four third-party data processors, and four entries in your Transfer Impact Assessment. One domain — your own — means none of that. Sealmetrics collects data through your subdomain, stores it in EU infrastructure, and contacts zero third-party domains. Read the full [security and compliance architecture](https://sealmetrics.com/security/) or [calculate how much data your current setup is losing](https://sealmetrics.com/data-loss-calculator/). Every external domain is a performance cost and a GDPR question. See what analytics with a single EU endpoint on your own subdomain looks like. [Book a demo](https://sealmetrics.com/demo/)[See pricing](https://sealmetrics.com/pricing/) ### Related articles [Every Cookie Set by Every Major Analytics Tool, Cataloged](https://sealmetrics.com/blog/analytics-tools-cookies-cataloged/)[We Tested 9 Analytics Tools Against Every Major Ad Blocker](https://sealmetrics.com/blog/analytics-tools-ad-blocker-test/) ## Related reading [Every Cookie Set by Every Major Analytics Tool, Cataloged](https://sealmetrics.com/blog/analytics-tools-cookies-cataloged/) 5 min read [The Hidden Conversion Killer: How Analytics Scripts Are Costing You Sales](https://sealmetrics.com/blog/analytics-scripts-costing-you-sales/) 3 min read [We Measured Every Analytics Script. Here Is What We Found.](https://sealmetrics.com/blog/we-measured-every-analytics-script/) 4 min read